// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_COMPOSITOR_SCOPED_LAYER_ANIMATION_SETTINGS_H_
#define UI_COMPOSITOR_SCOPED_LAYER_ANIMATION_SETTINGS_H_

#include <set>

#include "base/macros.h"
#include "base/time/time.h"
#include "ui/compositor/compositor_export.h"
#include "ui/compositor/layer_animator.h"
#include "ui/gfx/animation/tween.h"

namespace ui {

class ImplicitAnimationObserver;
class LayerAnimationObserver;
class InvertingObserver;

// Scoped settings allow you to temporarily change the animator's settings and
// these changes are reverted when the object is destroyed. NOTE: when the
// settings object is created, it applies the default transition duration
// (200ms).
class COMPOSITOR_EXPORT ScopedLayerAnimationSettings {
public:
    explicit ScopedLayerAnimationSettings(scoped_refptr<LayerAnimator> animator);
    virtual ~ScopedLayerAnimationSettings();

    void AddObserver(ImplicitAnimationObserver* observer);

    void SetTransitionDuration(base::TimeDelta duration);
    base::TimeDelta GetTransitionDuration() const;

    // Locks transition duration in |animator_|. When transition duration
    // is locked any subsequent changes to it are ignored until the
    // ScopedLayerAnimationSettings object that has locked the duration goes out
    // of scope.
    void LockTransitionDuration();

    void SetTweenType(gfx::Tween::Type tween_type);
    gfx::Tween::Type GetTweenType() const;

    void SetPreemptionStrategy(LayerAnimator::PreemptionStrategy strategy);
    LayerAnimator::PreemptionStrategy GetPreemptionStrategy() const;

    // Sets the base layer whose animation will be countered.
    void SetInverselyAnimatedBaseLayer(Layer* base);

    // Adds the layer to be counter-animated when a transform animation is
    // scheduled on the animator_. Must call SetInverselyAnimatedBaseLayer with
    // the layer associated with animator_ before animating.
    void AddInverselyAnimatedLayer(Layer* inverse_layer);

private:
    scoped_refptr<LayerAnimator> animator_;
    bool old_is_transition_duration_locked_;
    base::TimeDelta old_transition_duration_;
    gfx::Tween::Type old_tween_type_;
    LayerAnimator::PreemptionStrategy old_preemption_strategy_;
    std::set<ImplicitAnimationObserver*> observers_;
    scoped_ptr<InvertingObserver> inverse_observer_;

    DISALLOW_COPY_AND_ASSIGN(ScopedLayerAnimationSettings);
};

} // namespace ui

#endif // UI_COMPOSITOR_SCOPED_LAYER_ANIMATION_SETTINGS_H_
